Clinical Trial Tests Ultrasound Device to Boost Stroke Drugs

(National Institute of Drug Abuse)

A clinical trial found an ultrasound device safe for ischemic stroke patients and helpful for many of these patients in dissolving blood clots in their brains. Researchers from University of Texas Health Science Center in Houston, with colleagues from University of Alabama-Birmingham and medical centers in Germany, tested the device in an intermediate-stage trial with 20 participants, and reported the findings online yesterday in the journal Stroke.

Ischemic stroke occurs when fatty deposits form clots in blood vessels supplying the brain, which can lead quickly to damage of brain cells and tissue. Among the treatments for ischemic stroke are drugs known as tissue plasminogen activators that break up the blood clots and, if administered soon after stroke symptoms appear, can help prevent disability.

For most stroke patients, however, tissue plasminogen activators alone do not clear out all or even most of the fatty deposits, and ultrasound has been shown to improve the effectiveness of these drugs. Research at UT-Houston by senior author James Grotta and others led to a technology licensed to medical device company Cerevast Therapeutics Inc. in Redmond, Washington that is developing devices for hospital emergency room clinicians to apply ultrasound routinely with tissue plasminogen activators.

The Cerevast device tested in the trial, known as ClotBust ER, is strapped on the patient’s head and uses 18 ultrasound transmitters to flood the region where clots occur in the brain. While the tissue plasminogen activators work to break up the fibrous matrix holding together the blood clot, the ultrasound creates more fluid motion in the blood to accentuate the drug’s activity. The device, says Cerevast, has circuitry to target and control ultrasound waves, without the need of a specialist.

The trial, conducted in Houston and Birmingham, was designed primarily to test the safety of the device. The 12 men and 8 women participants had an average age of 63, and all received tissue plasminogen activators after reporting symptoms. All patients received two-hour exposure to ultrasound wearing the ClotBust ER.

The researchers report all of the patients tolerated the entire two-hour ultrasound treatments. In addition, none of the patients experienced bleeding in the brain, nor were any other adverse reactions reported to the ultrasound or the device.

While testing the device’s safety was the main objective of the trial, the researchers also measured its ability to restore blood flow in the brain. The team found 10 of the 20 patients had complete (8) or partial (2) restoration of blood flow, which the researchers say is a higher rate of success compared to reports from earlier studies using drugs alone or with a hand-held ultrasound device.

After 90 days, 13 of the 20 patients returned home or went into rehabilitation,with 6 of the patients reporting little or no disability. However, four patients died, either to the severity of their initial strokes or complications of their hospitalization (e.g., sepsis).

Based in part on these results, Cerevast is planning a late-stage clinical trial that the company aims to enroll 830 patients. That study will test the ultrasound device against a placebo.

Read more:

• FDA Approves Robotic Device for Stroke Rehabilitation
• Clinical Trial to Test Stroke Hemorrhage Treatment
• Goggle Device Helps Distinguish Between Vertigo and Stroke
• No Disability Improvement Seen from Clot Device After Stroke
• Clinical Trial of Early Stroke Stent Device Underway

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